Case example for Error

Case example for Systematic andRandom Error

Definition: Error in research is anything that interferes with making a confident conclusion about the study. The following examples illustrate both systematic error and random error in research:

Systematic error

In a study on weight loss, researchers determined at the end of the study that the scale that was used to measure participant’s weight was inaccurate. The scale added 10 pounds to the person’s actual weight every time the scale was used. Because the researcher realized that the scale consistently added ten pounds to each participant’s weight, they adjusted for this problem when analyzing the results.

Discussion questions

1. If you were the researcher, how would you handle this problem if you found out about it at the end of the study?

2. What are some things the researcher should have done in the first place to avoid this problem?

3. Is systematic error problematic in research in general if it can be corrected? What if the researcher doesn't know about the systematic error?

Random error

In a study on weight loss, a scale was used that added a few pounds more or a few pounds less each time the scale was used. The researcher did not know that the scale did not measure the participant’s exact weight. Because the researcher did not realize this, the researcher could not adjust for this problem when analyzing the results. This caused the study results to include some error.

Discussion questions

1. Are the results of this study accurate? Why or why not?

2. Does the use of a slightly inaccurate scale cause serious problems with the study results?

3. Is there anything that the researcher should have done to avoid this problem?

4. Which do you think is a more serious problem in research – systematic or random error?

5. Which type of error – random or systematic - is easier to control?

		ORI Curriculum Examples

	Case example for Systematic andRandom Error Definition: Error in research is anything that interferes with making a confident conclusion about the study. The following examples illustrate both systematic error and random error in research: Systematic error In a study on weight loss, researchers determined at the end of the study that the scale that was used to measure participant’s weight was inaccurate. The scale added 10 pounds to the person’s actual weight every time the scale was used. Because the researcher realized that the scale consistently added ten pounds to each participant’s weight, they adjusted for this problem when analyzing the results. Discussion questions 1. If you were the researcher, how would you handle this problem if you found out about it at the end of the study? 2. What are some things the researcher should have done in the first place to avoid this problem? 3. Is systematic error problematic in research in general if it can be corrected? What if the researcher doesn't know about the systematic error? Random error In a study on weight loss, a scale was used that added a few pounds more or a few pounds less each time the scale was used. The researcher did not know that the scale did not measure the participant’s exact weight. Because the researcher did not realize this, the researcher could not adjust for this problem when analyzing the results. This caused the study results to include some error. Discussion questions 1. Are the results of this study accurate? Why or why not? 2. Does the use of a slightly inaccurate scale cause serious problems with the study results? 3. Is there anything that the researcher should have done to avoid this problem? 4. Which do you think is a more serious problem in research – systematic or random error? 5. Which type of error – random or systematic - is easier to control?